Values and preferences in oral anticoagulation in patients with atrial fibrillation, physicians' and patients' perspectives: protocol for a two-phase study.
BACKGROUND
Oral anticoagulation prevents strokes in patients with atrial fibrillation but, for reasons that remain unclear, less than 40% of all patients with atrial fibrillation receive warfarin. The literature postulates that patient and clinician preferences may explain this low utilization.


METHODS
The proposed research seeks to answer the following questions: i) When assessed systematically, do patients' and clinicians' preferences explain the utilization of warfarin to prevent strokes associated with atrial fibrillation? ii) To what extent do patients' and clinicians' treatment preferences differ? iii) What factors explain any differences that exist in treatment preferences between patients and clinicians? To answer these questions we will conduct a two-phase study of patient and clinician preferences for health states and treatments. In the first phase of this study we will conduct structured interviews to determine their treatment preferences for warfarin vs. aspirin to prevent strokes associated with atrial fibrillation using the probability trade-off technique. In the same interview, we will conduct preference-elicitation exercises using the feeling thermometer to identify the utilities that patients place on taking medication (warfarin and aspirin), and on having a mild stroke, a severe stroke, and a major bleed. In the second phase of the study we will convene focus groups of clinicians and patients to explore their answers to the exercises in the first phase.


CONCLUSIONS
This is a study of patient and clinician preferences for health states and treatments. Because of its clinical importance and our previous work in this area, we will conduct our study in the clinical context of the decision to use antithrombotic agents to reduce the risk of stroke in patients with non-valvular chronic atrial fibrillation.
Alonso-Coello
Pablo
P
Iberoamerican Cochrane Center, Hospital Sant Pau, Sant Antoni Maria Claret 171, Barcelona, Spain. palonso@santpau.cat
Montori
Victor M
VM
Solà
Ivan
I
Schünemann
Holger J
HJ
Devereaux
Philipe
P
Charles
Cathy
C
Roura
Mercè
M
Díaz
M Gloria
MG
Souto
Juan Carlos
JC
Alonso
Rafael
R
Oliver
Sven
S
Ruiz
Rafael
R
Coll-Vinent
Blanca
B
Diez
Ana Isabel
AI
Gich
Ignasi
I
Guyatt
Gordon
G
D000368:Aged; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use; D001281:Atrial Fibrillation / Q000150:complications*; D005260:Female; D017144:Focus Groups; D006801:Humans; D008297:Male; D008875:Middle Aged; D010358:Patient Participation; D017060:Patient Satisfaction; D010818:Practice Patterns, Physicians'; D013030:Spain; D020521:Stroke / Q000209:etiology / Q000517:prevention & control*; D014859:Warfarin / Q000627:therapeutic use
D000925:Anticoagulants; D014859:Warfarin; D001241:Aspirin